INFO: task syz-executor.2:12928 blocked for more than 143 seconds. Not tainted 5.6.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28128 12928 7225 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4168 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4227 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 __fput+0x33e/0x880 fs/file_table.c:280 task_work_run+0xf4/0x1b0 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x416421 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ffea9a8a430 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000416421 RDX: 0000001b2e420000 RSI: 00000000000010a3 RDI: 0000000000000003 RBP: 0000000000000001 R08: 000000004403d0a7 R09: 00ffffffffffffff R10: 00007ffea9a8a510 R11: 0000000000000293 R12: 000000000076c900 R13: 000000000076c900 R14: 000000000005be0a R15: 000000000076bfac INFO: task syz-executor.1:12945 blocked for more than 143 seconds. Not tainted 5.6.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28400 12945 7161 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4168 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4227 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4ba/0x1290 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e59/0x27d0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c889 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f91014b0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f91014b16d4 RCX: 000000000045c889 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000798 R14: 00000000004ca4f4 R15: 000000000076bf0c INFO: task syz-executor.5:12946 blocked for more than 143 seconds. Not tainted 5.6.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28400 12946 7669 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4168 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4227 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4ba/0x1290 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e59/0x27d0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c889 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0496a31c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f0496a326d4 RCX: 000000000045c889 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000798 R14: 00000000004ca4f4 R15: 000000000076bf0c Showing all locks held in the system: 1 lock held by khungtaskd/1133: #0: ffffffff899bc240 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5743 1 lock held by in:imklog/6709: #0: ffff888094791870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 4 locks held by kworker/u4:2/12453: 1 lock held by syz-executor.2/12928: #0: ffff888218c67078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218c67078 (&fb_info->lock){+.+.}-{3:3}, at: fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 2 locks held by syz-executor.3/12939: 1 lock held by syz-executor.1/12945: #0: ffff888218c67078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218c67078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor.5/12946: #0: ffff888218c67078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218c67078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1133 Comm: khungtaskd Not tainted 5.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 12453 Comm: kworker/u4:2 Not tainted 5.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: krdsd rds_connect_worker RIP: 0010:__read_once_size include/linux/compiler.h:199 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:155 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x1c/0x50 kernel/kcov.c:187 Code: 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 65 48 8b 04 25 00 1f 02 00 65 8b 15 c8 fa 8e 7e 81 e2 00 01 1f 00 48 8b 34 24 75 2b <8b> 90 d8 13 00 00 83 fa 02 75 20 48 8b 88 e0 13 00 00 8b 80 dc 13 RSP: 0018:ffffc90005f2f9a0 EFLAGS: 00000046 RAX: ffff8880929f8500 RBX: 0000000000000001 RCX: ffffffff8178a42d RDX: 0000000000000000 RSI: ffffffff8178a436 RDI: 0000000000000005 RBP: ffffffff8690ea71 R08: ffff8880929f8500 R09: fffff52000b6c15e R10: ffffc90005b60aeb R11: fffff52000b6c15d R12: ffff8880929f8500 R13: ffff8880962a1280 R14: dffffc0000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c0000e7c80 CR3: 000000008ef2a000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: preempt_count arch/x86/include/asm/preempt.h:26 [inline] trace_hardirqs_on+0x26/0x220 kernel/trace/trace_preemptirq.c:25 __local_bh_enable_ip+0x159/0x270 kernel/softirq.c:194 spin_unlock_bh include/linux/spinlock.h:398 [inline] inet_csk_find_open_port net/ipv4/inet_connection_sock.c:235 [inline] inet_csk_get_port+0xdb1/0x2590 net/ipv4/inet_connection_sock.c:312 __inet_bind+0x5b2/0xbd0 net/ipv4/af_inet.c:524 inet_bind+0xf3/0x160 net/ipv4/af_inet.c:453 rds_tcp_conn_path_connect+0x536/0x880 net/rds/tcp_connect.c:144 rds_connect_worker+0x1a5/0x2c0 net/rds/threads.c:176 process_one_work+0x965/0x16a0 kernel/workqueue.c:2266 worker_thread+0x96/0xe20 kernel/workqueue.c:2412 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352